Expansion valve



Dec. 3, 1968 ERC A T ET AL 3,414,014

EXPANSION VALVE Filed March 25, 1965 Aqxxw 65 FlG-E INVENTORS L60 FMake/muz- 04PM A? Gem/4 United States Patent 3,414,014 EXPANSION VALVELeo Francis Merchant, Southfield, and Darwin Robert Grahl, Lincoln Park,Mich., assignors to American & Standard Inc., a corporation of DelawareFiled Mar. 23, 1965, Ser. No. 442,039 1 Claim. (Cl. 137-559) Thisinvention relates to refrigerant expansion valves, and particularly tovalves having desired features of low cost and long service life.

One object of the invention is to provide an expansion valve having animproved means for adjusting the superheat setting of the valve.

Another object is to provide an expansion valve having an inspectionlocated to afford visual indication of insufiieient refrigerant chargeor improper operation of the valve element.

A further object is to provide an expansion valve having a compact lowcost arrangement of parts which affords the dual advantages of superheatadjustment and refrigerant charge inspection.

Other objects of this invention will appear from the followingdescription and appended claims, reference being had to the accompanyingdrawings forming a part of this specification wherein like referencecharacters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 is a sectional view taken through one embodiment of theinvention;

FIG. 2 is a view having a portion thereof taken as a sectional view online 2--2 in FIG. 1.

Before explaining the present invention in detail, it is to beunderstood that the invention is not limited in its application to thedetails of construction and arrangement of parts illustrated in theaccompanying drawings, since the invention is capable of otherembodiments and of being practiced or carried out in various ways. Also,it is to be understood that the phraseology or terminology employedherein is for the purpose of description and not of limitation.

In the drawings there is shown a refrigerant expansion valve in the formof a forged brass housing having a central elongated body portion 12, afirst boss 16 extending right angularly from portion 12 adjacent one ofits ends, and a second boss 18 extending right angularly from portion 12adjacent its midpoint. Boss 16 is internally machined to provide acylindrical inlet passage 20 which intersects a cylindrical inletchamber 22 machined in an end of body portion 12. Located Within chamber22 is a spherical valve element 25 having a welded connection with astem 26, said stem extending through a port or passage 28, and beingslidably supported in a guide formed by a hollow annular boss 29. Asshown in the drawing, boss 29 projects into a cylindrical cavity 30machined in the end of body portion 12 remote from inlet chamber 22.

Positioned on an end of body portion 12 is a power element comprising apair of fixed plates 32 and 33, and an interposed corrugated metaldiaphragm 36, preferably constructed as shown in US. Patent 3,021,108.Plate 33 mounts one end of a tube 35 which extends away from the valveto a temperature sensing bulb (not shown). Thus, an increasing sensedtemperature effects an expansion of the bulb fluid, and a movement ofthe diaphragm toward port 28. The diaphragm movement is transmittedthrough stem 26 to valve element 25 to thus open port 28 and .permitrefrigerant flow into cylindrical'outlet passage 38.

To provide a variable superheat setting for the valve we utilize acompression spring 50 between a first adjust- 3,414,014 Patented Dec. 3,1968 able spring seat member 52 and a second spring seat member 53carried by stem 26. Members 52 takes the form of a tubular sleeve 55having an inwardly radiating flange 57 at the end thereof remote fromdiaphragm 36. As shown in FIG. 2, sleeve 55 may be factory adjustedaxially by a set screw 59 threaded into a tapped hole extending at anacute angle to the axis of stem 26. After the factory adjustment thescrew can be concealed by a ball 60, preferably retained by soldering.It will be seen that adjustment of screw 59 can be used to provide adesired loading on spring 50 for thus adjusting or determining thesuperheat setting of the valve. In the illustrated valve, springretainer 53 is located in spaced relation to diaphragm 36. However thediaphragm pressure pad 57 could be used as a spring retainer in theevent that some means were provided to affix stem 26 to the diaphragm.In most instances the stem merely abuts against the diaphragm pad, andit is therefore not possible to use the pad as a spring retainer.

In the illustrated valve the cylindrical inlet chamber 22 is closed byan inspection window 62 comprised of a glass disc 63 fused into a steelring65. The ring-disc assembly is held against an O -ring seal 66 by astaked over portion 68 of the valve body. Inspection window 62 isespecially beneficial in its illustrated location since it affordsvisual indication of the liquid refrigerant and the spherical valveelement. Thus, the detected presence of bubbles in the inlet chamberliquid will denote insuflieient refrigerant charge. Visual inspection ofthe valve element while the valve is in service may disclose thepresence of dirt, ice or sediment which can prevent proper closing. Itcan also disclose an improperly charged thermostatic bulb since aninsufficiently charged bulb will result in loss of control of the valveelement by the power element diaphragm 36, as by failure of the valveelement to open in response to an increasing sensed temperature.

It will be noted that the illustrated valve incorporates a novelarrangement of superheat adjustment and inspection window. The windowoccupies a most advantageous functional position in the valve, and atthe same time serves as a closure for chamber 22, thereby adding littleto the valve cost. Due to the fact that diaphragm 36 and window 62occupy opposite ends of the valve housing it is not practical to providea superheat calibration mechanism along the valve stem axis. However byusing a set screw 59 at an acute angle to the stem axis we are able toprovide the desired calibration at fairly low cost and withoutincreasing the valve size. Thus, a two tone capacity valve operating onR-12 refrigerant can have a dimension in the direction of stem 26 on theorder of two inches or less.

It will be seen from the above discussion that the invention isconcerned principally with inspection window 62 and superheat adjustmentmeans 59, said invention being capable of some modification and partsredesign varying from the specifically illustrated construction withoutdeparting from the spirit thereof as contemplated by the appended claim.

What is claimed:

1. A refrigerant expansion valve comprising a one piece valve housinghaving a central elongated body portion defining an axis; a first bossextending right angularly from the central portion adjacent one of itsends, and a second boss extending right angularly from the centralportion adjacent its midpoint; a first parallel Walled liquid inletpassage extending within the first boss on an axis at right angles tothe body portion axis; a parallel walled liquid inlet chamber extendinginto said one end of the central body portion on the body portion axisto intersect the inlet passage; a parallel walled vaporous outletpassage extending within the second boss and the midportion of thecentral body portion on an axis at right angles to the body portionaxis; a parallel walled cavity extending axially into the end of thebody portion remote from the inlet chamber; the central body portionhaving an annular boss of appreciable length projecting axially withinthe cavity to form an elongated stem guide; said central body portionhaving a flow passage extending between the inlet chamber and outletpassage in axial alignment with the stem guide; a valve element ofappreciably less diameter than the lateral dimension of the liquid inletchamber, said valve element being located in said liquid inlet chamberfor movement toward and away from the flow passage to control flowthrough the valve; :1 thermostatic operator including a diaphragmextending across the cavity in the central body portion for movementtoward the inlet chamber on temperature increase; an operator stemextending from the diaphragm through the stern guide and flow passage tooperate the valve element; a compression coil spring operativelydisposed in the valve housing for urging the stern in a directiontending to 20 close the valve element; and a transparent planarinspection window located in the end of the central body portion remotefrom diaphragm; said window extending in a plane normal to the sternaxis and constituting an end wall for the inlet chamber whereby toafiord a visual indication of insufiicient refrigerant charge orimproper operation of the valve element; the diameter of the windowbeing substantially the same as the diameter of the inlet chamber,whereby to afford a view of the entire chamber space.

References Cited UNITED STATES PATENTS 1,952,683 3/1934 Resek et al.23699 2,246,148 6/1941 Stephenson 62222 X 2,771,092 11/1956 Schenk 25161X 1,022,327 4/1912 Nelson 25161 2,625,178 1/1953 Price 25161 2,829,8364/1958 MacKenZie 137-559 X 2,941,712 6/1960 Cook 137559 X 3,021,1082/1962 Noakes 251-61 3,139,903 7/1964 Lonn 137-559 HENRY T. KLINKSIEK,Primary Examiner.

1. A REFRIGERANT EXPANSION VALVE COMPRISING A ONE PIECE VALVE HOUSINGHAVING A CENTRAL ELONGATED BODY PORTION DEFINING AN AXIS; A FIRST BOSSEXTENDING RIGHT ANGULARLY FROM THE CENTRAL PORTION ADJACENT ONE OF ITSENDS, AND A SECOND BOSS EXTENDING RIGHT ANGULARLY FROM THE CENTRALPORTION ADJACENT ITS MIDPOINT; A FIRST PARALLEL WALLED LIQUID INLETPASSAGE EXTENDING WITHIN THE FIRST BOSS ON AN AXIS AT RIGHT ANGLES TOTHE BODY PORTION AXIS; A PARALLEL WALLED LIQUID INLET CHAMBER EXTENDINGINTO SAID ONE END OF THE CENTRAL BODY PORTION ON THE BODY PORTION AXISTO INTERSECT THE INLET PASSAGE; A PARALLEL WALLED VAPOROUS OUTLETPASSAGE EXTENDING WITHIN THE SECOND BOSS AND THE MIDPORTION OF THECENTRAL BODY PORTION ON AN AXIS AT RIGHT ANGLES TO THE BODY PORTIONAXIS; A PARALLEL WALLED CAVITY EXTENDING AXIALLY INTO THE END OF THEBODY PORTION REMOTE FROM THE INLET CHAMBER; THE CENTRAL BODY PORTIONHAVING AN ANNULAR BOSS OF APPRECIABLE LENGTH PROJECTING AXIALLY WITHINTHE CAVITY TO FORM AN ELONGATED STEM GUIDE; SAID CENTRAL BODY PORTIONHAVING A FLOW PASSAGE EXTENDING BETWEEN THE INLET CHAMBER AND OUTLETPASSAGE IN AXIAL ALIGNMENT WITH THE STEM GUIDE; A VALVE ELEMENT OFAPPRECIABLY LESS DIAMETER THAN THE LATERAL DIMENSION OF THE LIQUID INLETCHAMBER, SAID VALVE ELEMENT BEING LOCATED IN SAID LIQUID INLET CHAMBERFOR MOVEMENT TOWARD AND AWAY FROM THE FLOW PASSAGE TO CONTROL FLOWTHROUGH THE VALVE; A THERMOSTATIC OPERATOR INCLUDING A DIAPHRAGMEXTENDING ACROSS THE CAVITY IN THE CENTRAL BODY PORTION FOR MOVEMENTTOWARD THE INLET CHAMBER ON TEMPERATURE INCREASE; AN OPERATOR STEMEXTENDING FROM THE DIAPHRAGM THROUGH THE STEM GUIDE AND FLOW PASSAGE TOOPERATE THE VALVE ELEMENT; A COMPRESSION COIL SPRING OPERATIVELYDISPOSED IN THE VALVE HOUSING FOR URGING THE STEM IN A DIRECTION TENDINGTO CLOSE THE VALVE ELEMENT; AND A TRANSPARENT PLANAR INSPECTION WINDOWLOCATED IN THE END OF THE CENTRAL BODY PORTION REMOTE FROM DIAPHRAGM;SAID WINDOW EXTENDING IN A PLANE NORMAL TO THE STEM AXIS ANDCONSTITUTING AN END WALL FOR THE INLET CHAMBER WHEREBY TO AFFORD AVISUAL INDICATION OF INSUFFICIENT REFRIGERANT CHARGE OR IMPROPEROPERATION OF THE VALVE ELEMENT; THE DIAMETER OF THE WINDOW BEINGSUBSTANTIALLY THE SAME AS THE DIAMETER OF THE INLET CHAMBER, WHEREBY TOAFFORD A VIEW OF THE ENTIRE CHAMBER SPACE.